Electric motors are about to get a major upgrade thanks to Benjamin Franklin

A handful of scientists and engineers—armed with materials and techniques unimaginable in the 1700s—are creating modern versions of Franklin’s “electrostatic motor," that are on the cusp of commercialization. It’s reminiscent of the early 1990s, when Sony began to produce and sell the first rechargeable lithium-ion batteries, a breakthrough that’s now ubiquitous.

Franklin’s “electrostatic motor" uses alternating positive and negative charges—the same kind that make your socks stick together after they come out of the dryer—to spin an axle, and doesn’t rely on a flow of current like conventional electric motors. Every few years, an eager Ph.D. student or engineer rediscovers this historical curiosity. But other than applications in tiny pumps and actuators etched on microchips, where this technology has been in use for decades, their work hasn’t made it out of the lab.

Electrostatic motors have several potentially huge advantages over regular motors. They are up to 80% as efficient as conventional motors after all the dependencies of regular electric motors are added in. They could also allow new kinds of control and precision in robots, where they could function more like our muscles.

And they don’t use rare-earth elements because they don’t have permanent magnets, and require as little as 5% as much copper as a conventional motor. Both materials have become increasingly scarce and expensive over the past decade, and supply chains for them are dominated by China.

These motors could lead to more efficient air-conditioning systems, factories, logistics hubs and data centers, and—since they can double as generators—better ways of generating renewable energy. They might even show up in tiny surveillance drones.

Out of the lab in Wisconsin

Leading the effort to resuscitate Franklin’s concept for motors big enough to use in industrial applications is C-Motive Technologies in Middleton, Wis. It is a 16-person startup founded by a pair of University of Wisconsin engineers named Justin Reed and Daniel Ludois who spent years tinkering with electrostatic motors to see if they could be improved.

They’re reaching out to companies, hoping to get their motors out into the real world. So far, FedEx and Rockwell Automation, the century-old supplier of automation to factories, are among those testing their motors.

“In motor technology, this is unique," says Kyle Crum, director of advanced technology Rockwell, which has made a small strategic investment in C-Motive, and is testing the company’s motors in one of its laboratories.

“Other motor technologies are kind of iterations on a theme, but they all work on the same physics," he adds. “This is turning everything on its head. I don’t use the term ‘disruptive technology’ lightly, but this could be that. It could change the game."

FedEx Supply Chain is testing the motors in conveyors at a distribution center near Fort Worth, Texas, says Mark Crowley, the automation technician at the site.

Electric motors 101

Conventional electric motors come in many types, but they all work by transforming a flow of electricity into motion. Picture the high school science experiment of wrapping copper wire around a nail. Current running through that coil can make the axle of a motor spin—or the process can run in reverse, yielding a generator. In a conventional electric motor, the movement of electrons induces a force that makes it go.

Electrostatic motors, for which the basic principle hasn’t changed since Franklin built the first practical example, are different. The force in these motors comes not from the movement of electrons but from the attraction and repulsion between negative and positive charges in components—the same type of static charge that gives you a shock when you touch a doorknob after shuffling across the carpet in winter.

Franklin’s original model—which he first demonstrated to the public in 1749 as a rotisserie to cook a turkey—is an illustrative example.

Rather than being pushed by a continuous electromagnetic field, the axle of Franklin’s motor included brass sewing thimbles that had their charge reversed as they passed one of four glass jars that store electric charge, one at each corner of the device. This meant every thimble had either a positive or negative charge, and was therefore attracted to the next glass jar and repelled by the one it just passed.

This is an ingenious way to turn electricity into motion, but it has a major flaw: It relies on air as the insulator keeping the positive and negative charges separated. Air is only so-so at this, which means that a Franklin-style electrostatic motor big enough to do useful work in industry would be weak and inefficient.

C-Motive’s founders discovered that a number of technologies had matured enough that, when combined, could yield electrostatic motors competitive with conventional ones. These enabling technologies include super fast-switching power electronics—like those in modern electric vehicles—that can toggle elements of the motor between states of positive and negative charge very quickly.

But the secret sauce of C-Motive’s motors is, in a sense, an actual secret sauce. Dogged exploration of combinations of various readily available industrial organic fluids led to a proprietary mix that can both multiply the strength of the electric field and insulate the motor’s spinning parts from each other—all without adding too much friction—says C-Motive Chief Executive Matt Maroon.

The biggest challenge to this new technology is the same that faces many other radical new ones—there’s already a huge infrastructure devoted to the existing technology, making companies reluctant to switch to something new, and relatively untested and costly, says James Edmondson, research director at emerging-technology analysis firm IDTechEX.

Electrostatic motors also require much higher voltages than traditional motors, which means they require a different kind of power electronics to feed current to the motor, potentially adding to the cost of the total system, he adds.

Micro drones

Electrostatic motors are inherently efficient because they don’t lose energy to the process of moving current around like a conventional motor, says Mingjing Qi, a professor of electrical engineering at Beihang University in Beijing. But until recently engineers didn’t have a very good understanding of how to optimize their efficiency, he adds.

A team of scientists led by Dr. Qi worked for six years to design an electrostatic motor light and powerful enough for a small, solar-powered drone. Their eventual goal is drones the size of insects, that can fly as long as sunlight shines on them, while carrying a payload that includes a tiny camera.

Electrostatic tech isn’t suitable for fast-spinning motors like those in the powertrains of electric vehicles and conventional drones, says C-Motive’s Maroon. But if they prove compelling in industrial applications, it’s possible that some systems that are currently designed for conventional motors could be redesigned to use electrostatic ones, such as home heating and cooling systems.

“With any startup and any new technology, there’s a bunch of ifs," says Crum, of Rockwell Automation. “But we’re talking about fans, pumps, servos for robots, conveyors—just drive down the road, and every industrial facility you see has these. Just the electrical efficiency you could gain from these alone is gigawatt after gigawatt, if widely adopted."

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Write to Christopher Mims at christopher.mims@wsj.com